hoffer



I. I.. HOFFER.

CALCULATOR. APPLICATION FILED OCT. 7. I9I9 l 1,365,997. Patented Jan. 18,1921.

I 2 SHEETS-SHEET I.

l. L. HOFFER.

CALCULATOR.

APPLICATION FILED OCT7L1919.

- Patented Jan. 18, 1921.

parent ldurlng the courseof the following "UNH- En .STATI-:s

PATENT oFFlfcE.

...IVAN L. KOFFER, O F MARCUS, WASHINGTCN.

cAncUnATc-m To all/whom t may concern: l n

Be it known that. I ,IVAN L. HOFFER, a

- citizen of the Uni-ted lStates, residing at Marcus, inthe county of V Stevens and,

State of Washington, have inventedvcertain new and useful Improvements in Calculators, of

which 'the' following isa specification.

:This invention relatesl to new and useful improvements in calculators, and has for lts object the provision offa calculator simple in ,construction and the parts of which may be -readily restored when destroyed by long A further object "is to provide a device of Y, theabove mentioned characterof the type commonly known as vest-pocket calculator.

further object is the 'provision `of ak device of this c'haracter which may be' used not only for addition and subtraction, but also for multiplication and,division.

Other objects and advantages Will be sipdiscussion.- y In thenc'companying drawings, wherein for the purpose of illustration is shown a preferred form of my device and wherein .like numerals designate like parts through- 'Figure lis a front elevation of my device; Fig. 2 is a similar view, one-half of the casing having been removed;

F 1g; 3 is a Section on the line 3 3 of Fig. 1; 1 j Fig.4 is an enlarged section on the line 5 4 of Fig.'2.

Fig. 5 is a view similar to that shownin Fig..2 illustratingthe use of bearing platesfor the rotatable shafts, and Fig. 6 is a section similar to that shown in Fig. 3, illustratingr the use of bearing plates,

Fig. 7 is a plan view of a bearinggpln'te; detached. l Referring now more particularly to the drawings, the numerallO indicates the casing as a whole. f

The casing 10 vcomprises complementary plates 11 an 12 secured to'flher by means of screws 134 or the llke. e vsections 1 1 and 12 are provided `with complementary apertures '14 and 1`5form1ng vapproximately circular openings inwhich tatable cylindrical members 16. Y

These members are secured to, or rotatable upon shafts 17 mounted in journals 18. The journals 18 are split, one-half being .the rotatable members.

It will benotedby an inspection of the are ndisposed roplates 18 are provided andthe journals 18 are formed therein.

-Secured upon one end of each 'of the rta'table members is a" gear 1 9 shown in the present instance as -beingprovided with .ten teeth. Secured to the opposite `end of the rotatable member is a 'mutilated gear 20 having a single tooth. In some 'forms of this calculator as, for example, va form adapted for compiling sums in English currency, the mutllated gear 20 may, on 'certain of the cylindrical members have more than one tooth. The ends ofthe 'cylindars are alter.-

nate'd, that isto say, the end ofthe first cylinder to the rightwhich is supplied with themutilated gear 20 is adjacent to-theend of the cylinderof the second member which is provided with the gear 19 Mounted in the;ends' of the casing or inthe bearing plates 18- are stub shafts 21 provided with a' pinion 22 meshing with the gears 19.

Specification of Letters Patent. Patented Jan, 18 1921 Application lled October 7, 1919. Serial lNo, 829,938.

Springs 23 are provided which bear against -V the pinions 22 preventing toov free rotation thereof. These pinions also insure correct alinementof theindicia 24 With the window.

The rotatable members 16 are provided upon one end thereof with an annular set of indicia 24, andv upon the opposite end the second annular set of indicia 25 reading in -reverseorder to the indicia of the set 24.

The body ofthe rotatable members is pro vided with spiral grooves 26.

Plate `11 which forms thef'side'of the device'hereinafter to be known as the addition side'theregf, is providedwith vertical slots A2l and small windows l28 placed immedi atelyabove each of the vertical slots 27.

The plate 12 or subtraction side of the de` 4vice 1s provided with similar slots 29 having arrangedthereabove small windows 30. The slots 27 and 29 allow access to the spiral grooves formed in the rotatable members 16 and thefwindows 28 and. 30a1'e alined with the indicia .arranged on the opposite ends of drawings thatwhen the stylus is inserted in one of the doers ofthe addition side of the device and drawn downwardly,'the rotatable verse of normal order.

v the left the stylus is inserted in the number 4 and drawn down, andthe number 4 ap i rotatable member,

however, the stylus is inserted in one of the doors of the subtraction side and drawn downwardly, the rotatable member is reverselyA rotated and the numbers appear in the window corresponding thereto .The operation of my When it is tion in addition the device is cleared. This is doneby subtracting the number a pearing in the windows. .In other wor s,the

rotatable Vmembers 16 are shifted until zero. .appear`s"in each of the windows.

Then pre- Sumingy that it isl desired to add numbers -l648'and 1597. Beginning at theright handl slot the operator inserts'the point of a pencil -or stylusl into the Slot 27 directly opposite the figure 8- in the vertical row of indicia adjacent to slot drawing the pencil or stylus downwardly until it engages the bottomy of the-slot. As-the'point-of the' pencil or stylus en a s 1n the. s iral roove formedl in the g ge p thisg member is shifted of its circumference and the pears in the first n the next. slot to eight-tenths number 8 accordingly a window to the right.

pears in the window above the slot, in the next slot the stylus is vinserted at the number 6 and drawn down and in the-next atthe 'number 1.] In the windows now appears the' number 1648. Returning to the right hand slot the operator inserts the stylus at point 7 and draws the stylus down, as the sum 4of 8 and 7 is greater4 than 10, the single tooth of the mutilated gear 20 engagesthe pinion 22 shifting the gear 19, of the next cylinder to the left, one tooth. The number in the windows now appearing 1655. At the next slot tothe left insert the stylus at the num ber 9 and `draw theI stylusy down. A s the sum of 9 and5 is more than 10 the operation above is again repeated and the number now appears in the windows 1745. At the next slot tothe left the operator inserts the stylus at the number 5, draws the stylus down, and as the sum of these-numbers is again more than 10 the carrying forward operation is again repeated, and the number 2245 .appears in the windows.' The operation is completed by inserting the stylus at the fourth window from the right at the number 1 and drawing 'the stylus down, giving the c'omplete sum 3245. Because of4 the peculiar arrangement of the indicia the same answer appears in the windows upon both sides of the casing. To subtract, the

minnend is first placed in the windows. The device is then turned over to bring the subin the reures from 0 to 9, arrange beside the slots 294 A device'is as follows:

desired to performV an opera- 'the face of the section 11,but w ap aring in the windows.

. tion or diic'ult of operation..

' ing from the s iri t of the inventionor the ity of rotatable e with a slot on each side thereof adjacent lof consecutive numbers arranged adjacente slots, said casing beingV provided in one face ada yted to display onsv number of one of traction side thereof into use and the subtrahend placed in the machine byplacing the stylusat the proper numbers in the prdper slots and drawing the stylus down. he face of the section 12 rovided with-fig- 65 similarly to the figures arranged beside the slots 27 on the face 11 andl shown in Fig. 1 of the drawings. The figures on the face 1 2 read in reverse order from the top of the slots 29, or the end toward the windows 30, Thev face is thus the same in ap rance as en a given number is carried down in the slots, -the rollers are operated in thereverse, direction. Asset forth above, this causes rotation of the rotatable members in the reverse direc tion andthe number is subtracted from that rom the foregoing it will be seen that '1 have evolveda machine which is capable of any of the simpler operations ,and-which at' the same time is` not complicated in construc- As many changes in the size, shape and arrangement of parts could be made without in any manner departing from the spirit of the invention, I do' not limitY myself tothe structure herein shown and described but may make any such changes without depart- 9 sco e' of the su joined claim.

aving thus described my invention,I I

In a computin device a casing, a pluralongated members moun in said casing, said casing being provided each-'rotatable member to permit rotation of said member in either direction, a" series said slots, the numbers on opposite sides 'of the casing being arranged in reverse order, one end of each of said rotatable members bem provided with a series of consecutive num rs corresponding to those adjacent the thereof with a series of windowsv each sai series of numbers on the rotatable members, and means forturning each of said r0- tatable 'members one step when the preceding rotatable member has been rotated a predetermined number of steps.

In testimon in presence o whereof I afiix my signature two witnesses.

. IVAN L. HOFFER.

Witnesses:

J. F. LAvIGNE,

WM. B. CARTER. 

